What is the antidote for beta-blocker overdose?

The antidote for beta-blocker overdose is glucagon. This is because glucagon works by increasing heart rate and improving myocardial contractility independent of the beta-adrenergic receptors that are compromised in an overdose situation. It stimulates the release of glucose from the liver, which can also help to counteract the negative inotropic effects caused by excess beta-blocker levels.

In contrast, N-acetylcysteine is primarily used for the treatment of acetaminophen overdose. Flumazenil is a benzodiazepine antagonist and is not effective for beta-blocker toxicity. Activated charcoal can be useful in certain poisonings to limit absorption of the drug if administered shortly after ingestion, but it does not reverse the effects of beta-blockers once they are in the system. Therefore, glucagon is specifically effective and indicated in addressing the complications associated with beta-blocker overdose.